E7402A preamp

Is there a general guideline for when to utilize the built-in preamp within an E7402A series EMC analyzer? Or........to put another way........is there any risk of damaging the analyzer or acquiring erroneous data by always leaving it in the "ON" state?

The use of a preamp is to amplify small input signals so that you can distinguish the signal from the noise. A good preamp itself contains an LNA (low noise amplifier) which has low noise and high gain, which improves signal to noise ratio for low level signals.

Leaving the preamp on all the time won't damage your instrument if you don't exceed maximum input power. however it will slightly increase your DANL (displayed average noise level). For low level signals, this tradeoff makes sense because the signal itself can be distinguished.

Read through the two guides to get a better sense of what signals would benefit from the preamp.

The use of a preamp is to amplify small input signals so that you can distinguish the signal from the noise. A good preamp itself contains an LNA (low noise amplifier) which has low noise and high gain, which improves signal to noise ratio for low level signals.

Leaving the preamp on all the time won't damage your instrument if you don't exceed maximum input power. however it will slightly increase your DANL (displayed average noise level). For low level signals, this tradeoff makes sense because the signal itself can be distinguished.

Read through the two guides to get a better sense of what signals would benefit from the preamp.